1. Field of the Invention
The invention relates to an input/output device comprising: a plurality of device enclosures; a plurality of units that are mounted on said multiple device enclosures; a table indicating a correspondence between an access object device specified by an external device and one of said multiple units; and a control unit that logically connects the external device with the corresponding unit based on said table; and a method of setting up identification information in such an input/output device.
2. Description of the Related Art
A type of device has been available having a rack loaded with a multiple of device enclosures, each of which is mounted with a multiple of hard disk drives (“HDD”). It is so constituted in such a device that a discrete slot identification (“ID”) code is assigned to each HDD mounted in each slot, 1 through n, provided in each enclosure, and a map (AL-PA map) is formed based on device enclosures' IDs and slot IDs read from hard disk drives each time when the power in turned on, so that a particular HDD can be accessed referring to said map when it is requested by a host computer.
A control device has also been disclosed, which consists of a plurality of printed circuit boards each equipped with a transmission LSI as an address function to identify which board is located where, and acquires the address of each printed circuit board with the help of said transmission LSI (Document 1).
A technology has also been disclosed wherein a plurality of drive units are connected to each of a plurality of mother boards assigning a discrete serial number to each drive unit, said discrete serial number comprising specific upper bits pre-assigned to each mother board (Document 2).
Document 1) Japanese Utility Model Gazette No. 2570074, especially FIG. 1 and [0006] of that.
Document 2) Japanese Patent Publication No. 04-137258, especially FIG. 1 and the Means of Solving the Problems, Specification of that.
Thus, although the slot ID of an HDD mounted on one of the slots, 1 through n, in a device enclosure can be uniquely defined, it is not unique when other device enclosures are considered, so that it is necessary to form a map obtaining the ID of the particular device enclosure and the slot ID of the HDD mounted in said device enclosure each time when the power is turned on in order to access the particular HDD (a unique address (physical location) corresponding to the HDD) in response to an access request received from the host computer, which causes problems such that it takes a lot of time to form such a map.
The method disclosed by the abovementioned Document 1 also has a problem that it causes a necessity to mount a transmission LSI.
The method disclosed by the abovementioned Document 2 also has a problem that it causes a necessity of presetting discrete serial number of each mother board.